1. Field of Invention
The present invention relates to a liquid crystal display (LCD) device and its driving method. More particularly, the present invention relates to an LCD device and its driving method, which can insert a black image in display without exporting a black signal to the displaying region.
2. Description of Related Art
The early applications of the thin-film transistor (TFT) LCD are usually on the notebook computer and terminal of personal computer. In this situation, most of the image signals are standstill image. In recent years, under the development by the LCD manufacturers, the liquid-crystal displaying technology has been gradually applied to the TFT-LCD in large size, and the image signals have changed from the standstill manner into dynamic manner. However, the current TFT-LCD is using the hold-type for display, that is, before the next set of data being written in, the pixels are held for display the current data. Thus, when this hold-type, of which the relation between the voltage and the timing is shown in FIG. 4, is operated in the dynamic image, it would cause a phenomenon of dragging image for the dynamic image.
Referring to FIG. 5, FIG. 5 is a circuit block, schematically illustrating a conventional LCD. The conventional LCD 500 includes a source driving circuit 502, a first gate integrated circuit 504, a second gate integrated circuit 506, a third gate integrated circuit 508 and a displaying region 510. Wherein, the displaying region 510 includes multiple image pixel block regions, formed from gate driving lines G1-G768 and source driving lines CH1-CH3072.
In the conventional technology, the first gate integrated circuit 504, the second gate integrated circuit 506, and the third gate integrated circuit 508 are receiving an output enabling signal. The output enabling signal includes a first output enabling signal, a second output enabling signal, and a third output enabling signal. The first output enabling signal controls the first gate integrated circuit 504, the second output enabling signal controls the second gate integrated circuit 506, and the third output enabling signal controls the third gate integrated circuit 508.
Referring to FIG. 5 and FIG. 6, in the conventional technology, after the gate driving line G1 being conducted, when the first output enabling signal is at the logic high, the scanning signal is not exported to the gate driving line G1. It is until the first output enabling signal is at the logic low, then the gate driving line G1 exports the scanning signal. After gate driving line G2 being conducted, when the first output enabling signal is at logic low, the scanning signal is then exported to the gate driving line G2. After gate driving line G3 being conducted, when the first output enabling signal is at logic low, the scanning signal is then exported to the gate driving line G3.
In summary, the current LCD device causes the phenomenon of dragging image due to a low speed for displaying image and an eye's image lag for a user.